A euphemism meaning to have diarrhea, explosive or non-explosive, and/or chronic digestive problems. Can be used as a noun or a verb. Originated from the Metal Gear videogame series from Johnny Sasaki, a luckless soldier with chronic digestive problems.
As a noun- Dude, I ate some rancid beans and had Johnny Sasaki all night.
As a verb- Not cool, man! You Johnny Sasaki'd all over my couch!